The reactivity of transition metal clusters has been of special interest in these days in the area of organometallic chemistry, owing to their capability of activating substrates through the cooperative effects of multiple metal centers. Although the multiple coordination to the metal centers enables facile bond activation of the substrates, the formed multiple M-C bond are an obstacle to the elimination of the substrates from the multinuclear site. However, we found that electrostatic repulsion of the substrate with the electron-rich multinuclear site comprised of (C₅Me₅)Ru fragments and stabilization by the recovery of aromaticity could be a driving force for the elimination from the multinuclear site. Thus, we attempted the reaction of polyhydrido clusters with pyridines to design a novel cluster catalysis. We report herein dehydrogenative coupling of 4-picoline and dehydrogenative oxidation of cyclic amines catalyzed by diruthenium complexes, [(CpsRu)(µ-H)₂]₂ (Cps=C₅Me₅ and C₅^tBu₃H₂), which involve unique chemical transformations at a diruthenium site.